Abstract: Blow-off device of a compressor unit, which compressor unit is of the type comprising a compressor (1) to which an outlet conduit (4) is connected with therein a cooler (5) with a moisture separator (6) and a return valve (7), whereby the blow-off device (8) comprises a blow-off conduit (9) which, on one hand, is connected to the outlet conduit (4) between the cooler (5) and the return valve (7) and, on the other hand, gives out into the atmosphere, and a blow-off valve (10) which is arranged in this blow-off conduit (9), wherein the blow-off device (8) comprises a moisture separator (11) which is placed in the blow-off conduit (9) between the outlet conduit (4) and the blow-off valve (10) and comprises means (15-16) for subjecting the blown-off fluid to a turbulence, such that moisture is separated.